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Discussion Starter · #1 ·
Hey all i want to add a manual toggle switch for hi speed rad fan i got a 2 pin toggle switch. To my understanding there are 2 relays for fan l99 and l100 this being the hi speed relay. If i wire from toggle switch to a ground source and then other wire from toggle switch to l100 relay ground pin should this work? I have a phase 2 v6 can someone also verify relay locations are they on a separate bracket to left of the fuse box under drivers dash?

thanks
 

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Discussion Starter · #2 ·
959182

Ok looking at the diagram above would i be right thinking if i ground the toggle switch to an earth source and other wire go to pin 87 on l100 hi speed fan this would turn it on with switch?
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Ok looking at the diagram above would i be right thinking if i ground the toggle switch to an earth source and other wire go to pin 87 on l100 hi speed fan this would turn it on with switch?
Thanks
You would connect Pin 86 (Red/Black) of Relay i100 through your switch to an earth. In this way, your switch is simulating the function of Motronic S11. This method keeps relay i100 in circuit protected by fuse G389.
Note: Pin 87 of both i100 and i99 are already permanently connected to earth.

If you must remove relay i100 from the circuit, connect your switch to pin 30 (Brown) of relay i100 and ground. Note that your fuse and wire must be capable of carrying the full current of the fan.
 
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Discussion Starter · #4 ·
You would connect Pin 86 (Red/Black) of Relay i100 through your switch to an earth. In this way, your switch is simulating the function of Motronic S11. This method keeps relay i100 in circuit protected by fuse G389.
Note: Pin 87 of both i100 and i99 are already permanently connected to earth.

If you must remove relay i100 from the circuit, connect your switch to pin 30 (Brown) of relay i100 and ground. Note that your fuse and wire must be capable of carrying the full current of the fan.
thanks for reply barbycar. So think your saying if i remove relay i100 i would put gauge 16 wire from pin 30 to my toggle switch and from other pole on toggle switch put this to earth? My toggle switch is rated at 25amp 12v so should be ok?
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thanks for reply barbycar. So think your saying if i remove relay i100 i would put gauge 16 wire from pin 30 to my toggle switch and from other pole on toggle switch put this to earth? My toggle switch is rated at 25amp 12v so should be ok?
Thanks
Yes, but my question is: Why?
In removing the relay you also remove any fan control from the ECU. Which means you have to either leave the high speed fan on all the time (your alternator will love you...) or you have to monitor the temperature gauge and remember to manually function the fan.
Wiring your switch to pin 86 leaves the ECU control in place AND allows you to manually function the fan. (And you don't need 16G wire to operate a relay).
 

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Discussion Starter · #6 ·
Yes, but my question is: Why?
In removing the relay you also remove any fan control from the ECU. Which means you have to either leave the high speed fan on all the time (your alternator will love you...) or you have to monitor the temperature gauge and remember to manually function the fan.
Wiring your switch to pin 86 leaves the ECU control in place AND allows you to manually function the fan. (And you don't need 16G wire to operate a relay).
ok i dont want to remove the relay still want fan to function via ecu just want the option to power the fan when i feel i need to. So if i run a wire from my switch to pin 86 and ground the other pole switch it will allow me still to manually run the fan when i want? Im actually still trying to confirm location of i100 relay according to manual its on an auxiliary bracket in front of main fuse box. Are these them i have highlighted in blue both relays are 50amp.

thanks

Hood Electrical wiring Electronic engineering Trunk Computer hardware
 

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According to the manual:
Font Art Number Brand Monochrome


i100 and i99 base colours: (note i99 is supposed to be 30A and there's supposed to be only one 50A on the aux bracket. If you have two 50A then I expect a relay failed previously and was replaced with whatever could be found)
Circle Event Font Electric blue Pattern


i100 wire colours:
LightBlue/Red - Pin85
Red/Black - Pin86
Black - Pin87
Brown - Pin30

If you can't see the wires behind, remove what you believe are i99 and i100 then jumper across pins 87 and 30 of each relay socket in turn (ie not at the same time), you'll know which is the high speed by listening to the fan. You won't need the ignition turned on for this test.
 
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Discussion Starter · #8 ·
Hey there thanks for help i found the relay by bridging pin 30 and 87 **** myself few sparks and smoke but fan turned on. This is how i wired it with pin 86 and then earthing to a clean point under dash its working but i would have thought it would only work with ignition on but its working without ignition on? Wont this drain the battery? This is how i wired it also is this wire thick enough wont cause fire or anything?
 

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the fan is directly connected to the battery (via a fuse), so that is why your switch will result in fan permanently on, regardless of ignition.on/off
Note that with the relatively high current demand of the fan, forgetting to switch off will very quickly result in an empty battery......
That's the danger of a mechanical switch.

If this is not what you want, you would actually need to switch via an additional (new) relay.
 

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Discussion Starter · #10 ·
Ok thanks i wont forget to switch fan off plus i have a kill switch for battery in boot that i generally always take of so battery is hardly ever connected up. Regarding wiring is it ok or should i get higher gauge?
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easy way to check is to feel if the wire gets hot with the fan running ;)
(ps lower gauge is thicker)

for a slightly more scientific way, check out following, with f.i. 2% voltage drop @ 12V
awg calcullations

you probably end up with around 6 awg ....
 

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Discussion Starter · #12 ·
6 awg thats right thick wire surely dont need that thick even 16 awg looks thick wire lol
 

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Switching a relay only needs 20G. However, the circuit is fed by a 10A fuse meaning as a minimum 18G to ensure the fuse blows before the wire burns. 16G automotive cable is appropriate and is far more flexible, read:'thinner', than household or hook-up wire.

More worrying is why it runs with ignition off. If you have wired pin 86 of the 2nd speed relay through your switch to earth - based on the diagram you included at post #2 - IT SHOULD NOT RUN with the ignition off. The only way to make this run with ignition off is by wiring your switch to pin 30 of the 2nd speed relay and if that's the case you are putting the full current of the fan through your wire and switch. When wired correctly, you will hear the relay click when you energise the switch.

Please review your setup - either the wiring diagram is not correct for your car or you are not wired to the correct pin. It is also possible that the relay socket is labelled wrong - note also that the 1st speed relay is wired in reverse from the 2nd speed relay.
 

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Discussion Starter · #14 ·
Switching a relay only needs 20G. However, the circuit is fed by a 10A fuse meaning as a minimum 18G to ensure the fuse blows before the wire burns. 16G automotive cable is appropriate and is far more flexible, read:'thinner', than household or hook-up wire.

More worrying is why it runs with ignition off. If you have wired pin 86 of the 2nd speed relay through your switch to earth - based on the diagram you included at post #2 - IT SHOULD NOT RUN with the ignition off. The only way to make this run with ignition off is by wiring your switch to pin 30 of the 2nd speed relay and if that's the case you are putting the full current of the fan through your wire and switch. When wired correctly, you will hear the relay click when you energise the switch.

Please review your setup - either the wiring diagram is not correct for your car or you are not wired to the correct pin. It is also possible that the relay socket is labelled wrong - note also that the 1st speed relay is wired in reverse from the 2nd speed relay.
thanks reply. I think maybe the wiring is wrong on my gtv the relay is energised via the temp sensor when temperature reaches 98c the relay is energised and hi speed fan comes on i think pin 85 is temp sensor.
 

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Discussion Starter · #15 ·
Maybe that diagram is from an older phase 1 mine is a phase 2 also its a v6 not a twin spark engine.
 

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Discussion Starter · #16 ·
I just put my multimeter on each pin to test volts got 12v with ign off
Pin 85 got 12v
Pin 86 got 12v
Pin 87 got 12v
Pin 30 go no voltage
explains why switch works with no ignition on. Lol
 

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Product Line Schematic Font Rectangle

If the car is post Oct 2000 as shown here, there are two relays to take the current for the two fans, so a manual switch would have to earth the light blue green wire, to trigger both. When this happens I think the wire to the ECU should not be earthed at the same time to protect the ECU from potential damage.
 

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Lee Blue's comments agree with the wiring diagram above , the three 12v feeds are unswitched. The controlling ECU has a switched supply.

Many years ago I had a flat battery due to relay contacts welding themselves together. Removing fuses was the only way to stop them. A German made relay I must add!
 

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Discussion Starter · #20 ·
Hi thanks. My gtv v6 is broke 2001 so yes that diagram should be correct. To be honest looking at the 3 relays on bracket not seen one with a light blue/green wire on the hi speed relay there is a light blue wire but with green stripe also which is pin 86 i think pin 85 has a solid red wire if i recollect. Well confused now lol
 
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